Develop Reference

How do I get a specific value from a key in a dictionary with multiple values per key?

I have a dictionary in this format:
my_dict = {"key1":["value1", "value2", "value3"]}
Is there an easy way to get key1's third value?
I guess I could get the whole list of values and then split it up, but there must be a better way

You can do a simple look up in the following ways -
my_dict['key1'][2]
#Output = 'value3'
OR (using dict.get)
my_dict.get('key1')[2]
#Output = 'value3'
OR (if you want 3rd element without specifying the key)
list(my_dict.values())[0][2]
#Output = 'value3'
OR (if you want last element without specifying the key)
list(my_dict.values())[0][-1]
#Output = 'value3'

my_dict['key1'][2]
You access the list in. the value like any other list

I prefer to use get i.e. my_dict.get('key1')[2]
If you use my_dict['key1'][2] , you will get a KeyError if key1 is not present in my_dict
Example -
>>> d = {1:3,4:6}
>>> d.get(7) # No Error
>>> d[7]
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
KeyError: 7

How to get values from a list of dictionary?

How to get the values from a list of dictionary??
For example: I want to get the output as 2?
data = [{'a':1,'b':2,'c':3}]
Below is the error am observing.
data['b']
Traceback (most recent call last):
File "", line 1, in
data['b']
TypeError: list indices must be integers, not str

The dictionary is the first element in data, so you can access it with:
data[0]['b']
If you have multiple dictionaries and you aim want to use them in a fallback order, you can use:
def obtain_value(list_of_dicts,key):
for dict in list_of_dicts:
if key in dict:
return dict[key]
raise KeyError('Could not find key \'%s\''%key)
and then call it with obtain_value(data,'b').

converting tuple to dictionary in python

I am trying to convert a line of string to dictionary where i am facing an error.
here is what i have and what i did:
line="nsd-1:quorum"
t=tuple(line.split(":"))
d=dict(t)
Traceback (most recent call last):
File "<pyshell#2>", line 1, in <module>
d=dict(t)
ValueError: dictionary update sequence element #0 has length 5; 2 is required
Basically, what i want to achieve is to have a key value pair.
So if i have set of values separated by a ":", i want to have it as a key whatever is before the colon and after the colon needs to be the value for the key.
example: if i take the above string, i want "nsd-1" as my key and "quorum" as value.
Any help is appreciated.
Thanks

Wrap it in a list:
>>> dict([t])
{'nsd-1': 'quorum'}
There's also no need to convert the return value of split to a tuple:
>>> dict([line.split(':')])
{'nsd-1': 'quorum'}

Put t inside an empty list, like this:
d=dict([t])

Weather Underground API to get historical data in Python

I am trying to pull historical data from the Weather Underground API. I adapted their Python example code (see below). When I run this I get an exception "TypeError: list indices must be integers, not str" The JSON stream includes a bunch of fields with daily summary information (Dailysummary), but I cannot get out and any of the values they have in this list.
I put the URL into a JSON viewer to look at the structure, and cannot figure out what I am doing wrong. Any help would be greatly appreciated.
import urllib2
import json
f = urllib2.urlopen('http://api.wunderground.com/api/d08c4738fb303c66/geolookup/conditions/q/CA/San_Francisco.json')
json_string = f.read()
parsed_json = json.loads(json_string)
location = parsed_json['location']['city']
temp_f = parsed_json['current_observation']['temp_f']
print "Current temperature in %s is: %s" % (location, temp_f)
f.close()
h = urllib2.urlopen('http://api.wunderground.com/api/d08c4738fb303c66/history_19760508/q/CA/San_Francisco.json')
json_string = h.read()
parsed_json = json.loads(json_string)
date = parsed_json['history']['utcdate']['pretty']
print date
print type(parsed_json['history'])
snow = parsed_json['history']['dailysummary']['0']
print snow
h.close()

It says your problem right in the error: You can't index a list with a string:
>>> [1]['0']
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: list indices must be integers, not str
>>> [1][0]
1
>>>
But you do it here:
snow = parsed_json['history']['dailysummary']['0']
To fix your problem, make your indexes integers:
snow = parsed_json['history']['dailysummary'][0]

I had a similar problem. Since it is a list of length 1, you can access the list item by the index 0. Now, if you check the type of the value item in index 0, it is a dictionary.
type(parsed_json['history']['dailysummary'][0])
<type 'dict'>
Now, that you know it is a dictionary, you can use keys to access the values. In your case.
print parsed_json['history']['dailysummary'][0]['snow']
This give you the value you are looking for.
Let me know if this helps.

The way to access the contents in parsed_json dict is using the keys. You can find the keys you're interested in using print parsed_json['history']['dailysummary'].keys()
If you do that you'll see that one of the keys is u'snow' which is a unicode string.
You can use that string to access the data you're looking for so instead of:
parsed_json['history']['dailysummary']['0']
what you need is:
parsed_json['history']['dailysummary']['snow']

How do I unpack a list with fewer variables?

k = [u'query_urls', u'"kick"', u'"00"', u'msg=1212', u'id=11']
>>> name, view, id, tokens = k
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: too many values to unpack
I need to provide 5 variables to unpack this list. Is there a way to unpack with fewer, so that tokens gets the rest of the list. I don't want to write another line to append to a list....
Thanks.
Of course I can slice a list, assign individually, etc. But I want to know how to do what I want using the syntax above.

In Python 3 you can do this: (edit: this is called extended iterable unpacking)
name, view, id, *tokens = k
In Python 2, you will have to do this:
(name, view, id), tokens = k[:3], k[3:]